/*
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at 
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *  
 */

using System;
using java = biz.ritter.javapi;
using org.apache.commons.collections;

namespace org.apache.commons.collections.functors
{

    /**
     * Transformer implementation that calls a Closure using the input object
     * and then returns the input.
     * 
     * @since Commons Collections 3.0
     * @version $Revision: 7136 $ $Date: 2011-06-04 21:03:12 +0200 (Sa, 04. Jun 2011) $
     *
     * @author Stephen Colebourne
     */
    public class ClosureTransformer : Transformer, java.io.Serializable
    {

        /** Serial version UID */
        private static readonly long serialVersionUID = 478466901448617286L;

        /** The closure to wrap */
        private readonly Closure iClosure;

        /**
         * Factory method that performs validation.
         * 
         * @param closure  the closure to call, not null
         * @return the <code>closure</code> transformer
         * @throws IllegalArgumentException if the closure is null
         */
        public static Transformer getInstance(Closure closure)
        {
            if (closure == null)
            {
                throw new java.lang.IllegalArgumentException("Closure must not be null");
            }
            return new ClosureTransformer(closure);
        }

        /**
         * Constructor that performs no validation.
         * Use <code>getInstance</code> if you want that.
         * 
         * @param closure  the closure to call, not null
         */
        public ClosureTransformer(Closure closure)
            : base()
        {
            iClosure = closure;
        }

        /**
         * Transforms the input to result by executing a closure.
         * 
         * @param input  the input object to transform
         * @return the transformed result
         */
        public Object transform(Object input)
        {
            iClosure.execute(input);
            return input;
        }

        /**
         * Gets the closure.
         * 
         * @return the closure
         * @since Commons Collections 3.1
         */
        public Closure getClosure()
        {
            return iClosure;
        }

    }
}